Injectable LUA scripting system, SDK generator, live property editor
2D game development library for Ruby and C++
A retro game engine for Python
Animation Compression Library
3D game engine/framework in C, with Luajit and Python bindings now
GemRB is a portable open-source implementation of the Infinity Engine
An isometric arcade-style game of skill, puzzles and exploration
Javascript library for making tile based games
SDL based generic 2D game engine
a UCI chess engine
2D Game Engine
A cross-platform 2D game engine
A cross platform Lua based game engine
Free and Open Game Programming Language for Windows and GNU/Linux
Real-time RPG for PC/tablet/phone; multiple quests and random dungeons
scriptable game engine with built-in support for 2D graphics and sound
Flexible and easy-to-use 2d game engine
Multi-platform game engine similar to old Megaman with a stage editor
Mahasona engine is an open source game engine.
A generic 2D engine for any kind of game